Supplementary MaterialsFIGURE S1: Rab5 and Rab7 localization during RGNNV infection

Supplementary MaterialsFIGURE S1: Rab5 and Rab7 localization during RGNNV infection. 15 viral families, including hepatitis A virus (HAV), hepatitis C virus (HCV), bovine virus diarrhea virus (BVDV), murine leukemia virus (MuLV), Zika virus, hepatitis B virus (HBV), and polyomaviruses (Shubin et al., 2016; Monel et al., 2017). Viral products (e.g., enveloped or capsid proteins) have been shown to act as vacuolization inducers (Shubin et al., 2015; Mcl-1-PUMA Modulator-8 Luo et al., 2016), and the mechanisms underlying the vacuolization effects differ. For example, 3C protease of hepatitis A virus (3Cpro) has induced numerous non-acidic cytoplasmic vacuoles, which were originated from the endosome and lysosome compartments (Shubin et al., 2015). Moreover, simian virus 40 (SV40) induces substantial cytoplasmic vacuoles at the late productive contamination stage, and the binding of viral major capsid protein VP1 to the cell surface ganglioside, GM1, triggers the formation of cytoplasmic vacuoles (Murata et al., 2008; Luo et al., 2016). Vacuolization evoked by an exogenous stimulus has been demonstrated to be derived from different membrane organelles, including mitochondria, endoplasmic reticulum (ER), lysosome, Golgi apparatus, and autolysosomes (Aki et al., 2012). Moreover, vacuolization usually accompanies different types of cell death, such as paraptosis-like cell death, necroptosis, and autophagy-associated cell death (Shubin et al., 2015; Monel et al., 2017). Therefore, an investigation of the vacuole origin and properties will contribute to elucidating the mechanisms of the pathomorphological effects of vacuolization inducers. For example, the MuLV envelope protein (Env)-induced cytoplasmic vacuoles were derived from the ER, and partially formed from fused endosomal/lysosomal organelles and autophagosomes (Whatley et al., 2008). During HBV contamination, the large HBV surface antigen (L-HBsAg) was also found to trigger ER vacuolization (Foo et al., 2002), whereas the vacuolating effect of L-HBsAg appears to be the cause of cell death (Xu et al., 1997). In addition, BVDV contamination induces vacuolization of acidic endosomal/lysosomal organelles, and the formation of vacuoles and cell loss of life is certainly autophagy-independent (Birk et al., 2008). In today’s research, we investigated the foundation of the vacuoles triggered by an infection with RGNNV in grouper cells. Furthermore, the crucial factors and events involved in vacuole formation and cell death were clarified. Together, our data will both shed important light around the characteristics of RGNNV-induced vacuolization and cell death, as well as contribute to our understanding of the mechanisms of nodavirus pathogenesis. Materials and Methods Cell Culture, Computer virus, and Reagents Grouper spleen (GS) cells were established and maintained in our lab (Huang et al., 2009). GS cells were produced in Leibovitzs L15 medium made up of 10% fetal bovine serum (Gibco) at FGF-18 28C. The RGNNV used in the study was prepared as described previously (Huang et al., 2011). For RGNNV contamination, the GS cells were infected with RGNNV at a multiplicity of contamination (MOI) of 2. Monensin sodium salt (an ionophore that mediates Na+/H+ exchange) and nigericin sodium salt (a K+/H+ ionophore) were purchased from MedChemExpress (MCE). z-FA-FMK (inhibitor of cysteine proteases, including cathepsins B, S, and L) was purchased from Selleck. Chloroquine (CQ), bafilomycin A1 (Baf), E64D (L-trans-epoxysuccinyl (OEt)-leu-3-methylbutylamide-ethyl ester, pan-cysteine cathepsin inhibitor), and CA-074 (L-trans-epoxysuccinyl-Ile-Pro-OH propylamide, an inhibitor of cathepsin B) were purchased from Sigma-Aldrich. All reagents were dissolved in DMSO. 3-Methyladenine (3-MA) was purchased from Selleck and dissolved in sterile water. Lyso-Tracker (Red DND-99), Image-it lifeless green viability stain, Mito-Tracker (Red CMXRos), and ER-Tracker (Red) were obtained from Invitrogen. In addition, the plasmids, pEGFP-N3 (control vector), pEGFP-LC3 (GFP-tagged LC3 plasmid, a versatile marker of autophagy), pEGFP-Rab5 (marker for the early endosome), and pEGFP-Rab7 (marker for the late endosome), used in this study were stored in our lab as previously described (Wang et al., 2014). Computer virus Contamination GS cells were produced in either 24- or 6-well plates pretreated with DMSO, water, or different reagents (the optimal concentration used in this study was determined using a cell viability assay) for 2 h. The GS cells were infected with RGNNV at a MOI of 2 and cultured at 28C. At 24 Mcl-1-PUMA Modulator-8 h post-infection (p.i.), the cytopathic effect (CPE) of the cells was observed under microscopy (Zeiss). Cell Viability Assay To evaluate cell viability, cells treated with DMSO- or different reagents (Z-FA-FMK, CA-074, Baf, CQ, Monensin, Nigericin or 3-MA) were incubated with Image-It Dead green viability stain for 15 min, and the cells were imaged under a fluorescence Mcl-1-PUMA Modulator-8 microscope. The Mcl-1-PUMA Modulator-8 percentage of cell death was also determined by trypan blue exclusion (Mullick et al., 2013). Briefly, the cells were collected by trypsinization and stained with trypan blue. Cell mortality (%) was presented as.